Compressed fibrous material



June 10, 1941. E. F. VON ENDE EIAL COMPRESSED FIBROUS MATERIAL Filed Aug. 18, 1937 /nve/7zon EmzI/z' UOIZ Ende v He/nrich Geff'cken Patented June 10, 1941 OFFICE 2,245,169 COMPRESSED FIBROUS MATERIAL Emil Freiherr von E Heinrich Geii'ck 1 Claim. The present invention relates to compressed fibrous material and a method of making such material, more particularly to a compressed composit e product made from laminae or sheets of wood similar to the product known as plywood but having improved characteristics and advantages over the latter.

According to the customary manner of manufacturing plywood, wooden sheets or slabs are stacked or piled upon one another with the fibres or grain of thewood in one sheet being at an angle to the grainof the wood in the adjacent sheet, whereupon the sheets are glued together under pressure to form a composite plank or board. The thus obtained product is substantially non-warping and capable of resisting other distortions and tearing at its edges when out into a desired shape. However. these properties hold true for substantially only one; i. e., the planar dimension of the superposed sheets or strata in such a manner that the material is practically restricted in use to the form of boards or planks and cannot be wrought into articles of other shape.

It is an object of the present invention to provide a new improved product of the above general character and a method of making the same whereby the beneficial features of the composite material are extended to the direction at right angle to the surface of the sheets or strata in the compressed material in addition to other desirable features and advantages as will become apparent from the following description of a practical embodiment of the invention taken with reference to the accompanying drawing wherein:

Figure 1 shows an enlarged partial cross-section through a stack of wooden sheets or strata prior to the compressing operation;

Figure 2 shows the stack according to Figure 1 after compression and forming into a composite block; 1

Figure 3 illustrates diagrammatically a press suitable for practising the invention;

Figure 4-is a top view of the completed block obtained by the invention.

With the above objects in view, the present invention contemplates the provision of a plurality of relatively thin wooden sheets or laminae stacked upon each other with the grain of the wood in one sheet being at an angle, preferably a right angle, to the grain of the wood in the adjacent sheet, said sheets being corrugated or otherwise formed with regular or irregular depressions and elevations fitting and interlocking with nde, Haslach i./K., and

en, Berlin, Germany Application August 18, 1937, Serial No. 159,733

' Germany May 2, 1936 each other and being intimately united into a composite block by gluing under heat and pressure.

Referring more drawing, item 4 sheets relatively arranged in such a manner that the grain of the wood in one sheet forms an angle, preferably a right angle, with the grain of the wood in the adjacent sheet such as shown in greater detail in the enlarged cross-section of Figure 1 wherein the broken lines and dots repreparticularly to Figure 3 of the sent the grain in alternate sheets in perpendicular relation to each other. The stack 4 is placed in the press l'between upper and lower blocks or platens 2 and 3, respectively, heated by any suitable means (not shown) and compressed in a manner well understood. The preferably swollen or laminae have been previouswhereby a solid composite block will be obtained by the compressing and heating operation. The inner sides of the platens 2 and 3 are formed with profiled or corrugated faces fitting each other when the press is completely closed with the block 4 removed, thereby forcing the individual sheets in the stack to assume a wavy or corrugated shape by first applying pressure to restricted areas and gradually extending and increasing the pressure until covering the entire face of the stack. In this manner a composite solid block is obtained as shown in cross-section in Figure 2. This block is then cut or otherwise formed or wrought into units of any desired shape not limited to boards or planks as in the case of ordinary plywood of any desired size or shape for use as a variety of articles such as dishes. plates, gun stocks, turnery articles, and for numerous other uses.

As pointed out hereinbei'ore, the deforming of the sheets in a direction at right angle to their surface in the completed block is preferably of a regular, corrugated or wavy pattern as illustrated. 'Lne crests and valleys of the corrugations preferably extend at an angle of 45 with the grain or direction of the fibres in all of the sheets provided the grain in one grain in the adjacent sheet at an angle of as shown more clearly in Figure 4. In the latter,

represents a stack of wooden a gluing or bonding substance sheet crosses the the direction of the according to the present invention a compact laminated wooden product of great tensile and compressive strength and which inherently possesses great resistive properties against warping. splintering, and other deforming forces exerted thereon in substantially all directions and may be manufactured in block form and wrought into any desired shape such as by cutting, tuming. planing, etc. as compared with the ordinary plywood material having resistive properties limited to substantially a single plane and being useful only in the form of planks or boards. This may be explained by the fact that the grain of the several sheets has its direction changed so that any stress or mechanical working operation imposedupon the product will have a component at least partially in the direction of the grain.

As will be evident the invention is not limited to the specific constructions and methods of manuiacture described herein for illustration but that various embodiments and modifications may be resorted to coming within the general scope and spirit of the invention as defined in the appended claim We claim:

A method of manufacturing compressed wooden materials comprising assembling a plurality of readily pliable glue surfaced sheets of wood into a stack with alternate sheets having their grain extending at-right angles to one another, uniting and simultaneously torrugated the sheets in said stack by the application of heat and increasing pressure applied along lines extending at an angle of approximately 45 to the grain of all of the sheets, and permitting the stack to cool while still under pressure whereby it will set in the form oi a solid compact block, the said corrugations increasing the resistance or the block to deformation and substantially eliminating any tendency to tear at its edges when subjected to mechanical operations.

EMIL FREIHERR VON ENDE. HEINRICH GEFFCKEN. 

